Chemistry study guide question(s) help...thanks! :)?

3. They have the same charge, e.g. both negative. Sorry I couldn't help with the first one.

a million. Convert grams of N to moles of N utilising the atomic mass. Convert moles of N to molecules of N utilising avagadros extensive type. be effective to apply dimensional prognosis so as that your instruments cancel. this could propose dividing grams of N by using the atomic mass of N and then multiplying by using avagadros extensive type. 2. Do the choice of above. Convert molecules of Ni to moles of Ni utilising avagadros extensive type and then convert moles to grams utilising the atomic weight of Ni. 3. a million/2-existence ability that a million/2 the pattern decays. So the question is how does this translate into seventy 5%. permit's think of roughly it. in one a million/2 existence, a million/2 is long gone. Now we basically have 50%. After a 2d a million/2-existence, a million/2 of it fairly is long gone. That leaves a million/2 of a million/2. by using fact of this seventy 5% is long gone. So that's going to take 2 a million/2-lives. 4. there is an equation for a million/2 existence. volume of pattern last = unique volume of pattern * (0.5)^(type of a million/2 lives) which you will answer this question you ought to choose first what proportion a million/2 lives 27 hours is and plug that throughout. (this can be the Time/a million/2 existence, making effective the instruments are the comparable). then you definately can enter a million for the beginning volume of pattern and remedy for the relax volume. Then in case you divide the relax volume of pattern by using a million and multiply by using one hundred% you've gotten the p.c. last. 5. to place in writing molecular formula, you first decide the fee on each and each molecule. subsequently you want the fee on V and P (phosphide). The question tells you the fee on Vanadium by using the extensive type interior the parentheses so that's V+2. Phosphide you ought to make a choice from the periodic table. locate phosphorus. initiate on the wonderful of the table and count extensive type what proportion blocks from final row that's. (must be 4) considering we counted from the wonderful, all of us know that's unfavorable so the fee on P is -4. Then we take the fee on V and make it the subscript on P and vice a versa. this suggests we've V4P2, the place 4 and a pair of are subscripts. wish this helps.